Page 28 - Curriculum Visions Dynamic Book

Aluminium as a conductor
Aluminium is a good conductor of both heat and electricity. It has found widespread applications in the electricity supply industry and also in places where good heat conductivity is needed, such as in radiators and cookware.
An electrical conductor
Aluminium conducts electricity about two-thirds as well as copper. When made as a special alloy, or mixture of metals, aluminium is an even better conductor than copper on a weight for weight basis. This is because aluminium is only one-third
as dense as copper. It is also very much cheaper to use than copper, especially where large cables are needed, such
as those slung between pylons or the main cables buried beneath the street. Today more than nine
out of every ten kilometres of large-diameter electrical cable are made from aluminium
rather than traditional copper.
 Overhead cables are made of twisted strands of aluminium surrounding a steel
cable core. The steel is used to give the cable strength. Aluminium cables
are lighter and therefore require less substantial pylons than
if copper were used.
 A section of
underground cable,
as would be used to
supply the electricity to a street, shows three cores made from aluminium and insulated from each other by plastic coatings.
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